Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480279-01 Printed in U.S.A. Form 48LC-4-6-02SM Pg 1 2-2020 Replaces: 48LC-4-6-01SM
Service and Maintenance Instructions
TABLE OF CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1
UNIT ARRANGEMENT AND ACCESS . . . . . . . . . . . . 3
Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 3
Seasonal Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 3
SUPPLY FAN (BLOWER) SECTION . . . . . . . . . . . . . . 4
Supply Fan (Belt-Drive) . . . . . .
. . . . . . . . . . . . . . . . . 4
COOLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Condenser Coil Maintenance and Cleaning
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Refrigerant System Pressure
Access Ports . . . . . . . 7
Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Condenser-Fan Adjustment . . . . . . . . . . . . . . . . . . . . 8
Troubleshooting Cooling System . . . . . . . . . . . . . . . 8
PURON® (R-410A) REFRIGERANT . . . . . . . . . . . . . 10
Refrigerant Charge . . . . .
. . . . . . . . . . . . . . . . . . . . . 10
COOLING CHARGING CHARTS . . . . . . . . . . . . . . . . 11
THERMOSTATIC EXPANSION VALVE (TXV) . . . . . 14
TXV Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
CONVENIENCE OUTLETS . . . . . . . . . . . . . . . . . . . . 14
Non-Powered Type . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Unit-Powered Type . . . . . . . . . . . . .
. . . . . . . . . . . . . 14
SMOKE DETECTORS . . . . . . . . . . . . . . . . . . . . . . . . 15
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Smoke Detector Locations . . . . . . . . . . . . . . . . . . . . 16
Completing Installation of Return Air Smoke
Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
FIOP Smoke Detector Wiring and Response . . . . . 17
Sensor and Controller Tests . . . . . . . . . . . . . . . . . . 18
Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Resetting Alarm and Trouble Condition Trips . . . . 21
Troubleshooting . . . . . .
. . . . . . . . . . . . . . . . . . . . . . 21
PROTECTIVE DEVICES . . . . . . . . . . . . . . . . . . . . . . 21
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . 21
Supply (Indoor) Fan Motor Protection . . . . . . . . . . 21
Relief Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Control Circuit, 24-V . . . . . . . . . . . . . . . . . . . . . . . . . 21
GAS HEATING
SYSTEM . . . . . . . . . . . . . . . . . . . . . . 21
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Fuel Types and Pressures . . . . . . . . . . . . . . . . . . . . 22
Flue Gas Passageways . . . . . . . . . . . . . . . . . . . . . . . 23
Combustion-Air Blower . . . . . . . . . . . . . . . . . . . . . . 23
Burners and Igniters . . . . . . . . . . . . . . . . . . . . . .
. . . 24
Burner Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Orifice Replacement . . . . . . . . . . . . . . . . . . . . . . . . .26
Minimum Heating Entering Air Temperature . . . . . .26
Troubleshooting Heating System . . . . . . . . . . . . . . .26
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
START-UP, GENERAL . . . . . . . . . . . . . . . . . . .
. . . . .32
Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Outdoor-Air Inlet Screens . . . . . . . . . . . . . . . . . . . . .33
Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . . .33
Internal Wiring .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Refrigerant Service Ports . . . . . . . . . . . . . . . . . . . . .33
Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . .33
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Main Burners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Heating . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . .33
Ventilation (Continuous Fan) . . . . . . . . . . . . . . . . . .33
Electrical Connections . . . . . . . . . . . . . . . . . . . . . . .33
RTU Open Control System . . . . . . . . . . . . . . . . . . . .35
SystemVu™ (Factory Option) . . . . . . . . . . . . . . . . . .35
Economi$er® X (Factory Option) . . . . . . . . . . . . . . .35
VFD OPERATION WITH REMOTE KEYPAD . . . . . . .46
To Connect the VFD Keypad using the RJ
-45
Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Start Up with Assistant . . . . . . . . . . . . . . . . . . . . . . .46
Start Up by Changing Parameters Individually . . . .47
VFD Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Fan Speed Relay Board . . . . . . . . . . . . . . . . . . . . . . .58
Configuration Jumpers . . . . . . . . . . . .
. . . . . . . . . . .58
Variable Frequency Drive . . . . . . . . . . . . . . . . . . . . .58
FASTENER TORQUE VALUES . . . . . . . . . . . . . . . . .60
APPENDIX A — MODEL NUMBER
NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . .61
APPENDIX B — PHYSICAL DATA . . . . . . . . . . . . . . .62
APPENDIX C — FAN DATA . . . . . . . . . . . . . . . . . . . .63
APPENDIX D — WIRING DIAGRAMS . . . . .
. . . . . . .71
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . .CL-1
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified service personnel should install, repair, or
service air-conditioning equipment.
Untrained personnel can perform basic maintenance functions of
cleaning coils and filters and replacing filters. All other operations
should be performed by trained service personnel. When working
on air-conditioning equipment, observe precautions in the
literature, tags and labels attached to the unit, and other safety
precautions that may apply.
Follow all safety codes, including ANSI (American National
Standards Institute) Z223.1. Wear safety glasses and work gloves.
WeatherExpert
®
48LC 04-06
Single Package Rooftop
Gas Heating/Electric Cooling Unit
with Puron
®
(R-410A) Refrigerant
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